Adenosine is known to be an endogenous modulator of a number of physiological functions. At the cardiovascular system level, adenosine is a strong vasodilator and a cardiac depressor. On the central nervous system, adenosine induces sedative, anxiolytic and antiepileptic effects. On the respiratory system, adenosine induces bronchoconstriction. At the kidney level, it exerts a biphasic action, inducing vasoconstriction at low concentrations and vasodilation at high doses. Adenosine acts as a lipolysis inhibitor on fat cells and as an antiaggregant on platelets.
Adenosine action is mediated by the interaction with different membrane specific receptors which belong to the family of receptors coupled with G proteins. Biochemical and pharmacological studies, together with advances in molecular biology, have allowed the identification of at least four subtypes of adenosine receptors: A1, A2A, A2b and A3. A1 and A3 are high-affinity, inhibiting the activity of the enzyme adenylate cyclase, and A2A and A2b are low-affinity, stimulating the activity of the same enzyme.
Analogs of adenosine able to interact as antagonists with the A1, A2A, A2b and A3 receptors have also been identified. Selective antagonists for the A2A receptor are of pharmacological interest because of their reduced level of side effects. In the central nervous system, A2A antagonists can have antidepressant properties and stimulate cognitive functions. Moreover, data has shown that A2A receptors are present in high density in the basal ganglia, known to be important in the control of movement. Hence, A2A antagonists can improve motor impairment due to neurodegenerative diseases, for example, Parkinson's disease, senile dementia as in Alzheimer's disease, and psychoses of organic origin.
Some xanthine-related compounds have been found to be A1 receptor selective antagonists, and xanthine and non-xanthine compounds have been found to have high A2A affinity with varying degrees of A2A vs. A1 selectivity. Triazolo-pyrimidine adenosine A2A receptor antagonists with different substitution at the 7-position have been disclosed previously, for example in WO 95/01356; U.S. Pat. No. 5,565,460; WO 97/05138; and WO 98/52568.
Parkinson's disease is characterized by progressive degeneration of the nigrostriatal dopaminergic pathway. The subsequent reduction in striatal dopamine levels is responsible for motor symptoms associated with Parkinson's disease, e.g., the loss of fine motor control or motor impairment manifested in those suffering from the disease. Current methodologies for alleviating motor symptoms associated with Parkinson's disease seek to replace dopamine either within the presynaptic terminal, for example, by administration of L-Dopa, directly through stimulation of the postsynaptic D2 receptors, or by inhibiting metabolism, for example, by administration of monoamine oxidase type B (MAO-B) or catechol-O-methyltransferase (COMT). Long term use of such therapies is often associated with adverse events. For example, long term therapy with L-Dopa (currently the standard of care) is often associated with adverse events (e.g. motor complications), for example, “wearing-off”, “random on-off” oscillations, or dyskinesia. These motor complications arising from therapy administered to manage Parkinson's disease often become progressively more severe with continued treatment.
As mentioned above, A2A receptors are present in high density in the basal ganglia and are known to be important in the control of fine motor movement. Highly selective A2A antagonists have demonstrated their efficacy in reducing motor symptoms associated with neurodegenerative diseases. Accordingly, compounds which are A2A receptor antagonists are believed to be useful in alleviating motor symptoms associated with Parkinson's disease. For example, U.S. Pat. No. 8,389,532 to Boyle et al. (the '532 patent) describes the preparation of the compound of Formula I:

In the '532 patent, Example 1 shows methods of preparing compounds of Formula I, and describes also that the compound of Formula I can be prepared as a pharmaceutically acceptable salt which may be useful for treating Parkinson's disease.
Patients suffering from Parkinson's disease generally suffer from gastric disorders related to over-production of stomach acid, for example, acid reflux and GERD. Accordingly, it is common among patients suffering from Parkinson's disease to be on a course of medication to address such issues, for example, a proton pump inhibitor, for example pantoprazole, omeprazole or ranitidine. Desirably, the compound of Formula I for use in providing treatment of Parkinson's disease symptoms requires that it be formulated in a manner that it can be provided as an orally administered tablet compatible with other medications commonly in use in the treatment of symptoms of Parkinson's disease.